January 15, 2013

Climate and history (in Eastern Europe)

PNAS doi: 10.1073/pnas.1211485110

Filling the Eastern European gap in millennium-long temperature reconstructions

Ulf Büntgen et al.

Tree ring–based temperature reconstructions form the scientific backbone of the current global change debate. Although some European records extend into medieval times, high-resolution, long-term, regional-scale paleoclimatic evidence is missing for the eastern part of the continent. Here we compile 545 samples of living trees and historical timbers from the greater Tatra region to reconstruct interannual to centennial-long variations in Eastern European May–June temperature back to 1040 AD. Recent anthropogenic warming exceeds the range of past natural climate variability. Increased plague outbreaks and political conflicts, as well as decreased settlement activities, coincided with temperature depressions. The Black Death in the mid-14th century, the Thirty Years War in the early 17th century, and the French Invasion of Russia in the early 19th century all occurred during the coldest episodes of the last millennium. A comparison with summer temperature reconstructions from Scandinavia, the Alps, and the Pyrenees emphasizes the seasonal and spatial specificity of our results, questioning those large-scale reconstructions that simply average individual sites.

3 comments:

While climate is rarely mentioned as a factor in the 30-years war, I have argued previously that significant cooling would have been a strong motivation first for the Danish (defeated), and subsequently the Swedish southward invasions - as has happened before - to secure hegemony over agricultural resources in warmer areas.

Agricultural production difficulties also make it easier to find conscripts - but likewise makes it more difficult to maintain standing armies. As a consequence, much of Germany lost ~50% of its population during this time.

"I have argued previously that significant cooling would have been a strong motivation first for the Danish (defeated), and subsequently the Swedish southward invasions - as has happened before - to secure hegemony over agricultural resources in warmer areas."

Strong motivation, yes.

"To secure hegemony over agricultural resources", no.

The Viking raids in the early second millenium, like the earlier Vandal attacks on Rome, weren't wars of conquest for the most part. A better analogy would be the pirates of Somolia and the Mallucas.

Raiding and banditry is probably not a stable long term basis for an economy but when all other means of supporting your society fall apart, it can come to be an economic basis on a par with terrestrial hunting and gathering, fishing, nomadic pastoralism, hoe farming, plough farming, or a commercial economy, at least for a while, for an entire society.

A story where the Danes and Swedes transition to banditry on an overall societal level in the face of the collapse of their prior means of creating wealth from their (very late) adoption of farming seems like a better fit than an empire building tyrant war of conquest model.